I recently asked a group of mostly American students to identify important military figures in wars involving the United States. They easily produced names from the War of Independence, the Civil War and World War II. But they went blank trying to remember heroes from other wars, including one in particular: the Mexican-American War of 1846–1848. Most could sing the opening line from the Marine Hymn, “From the Halls of Montezuma …” but none knew where it came from.

Are there some wars that nations prefer to forget? Such collective amnesia is odd, since the Mexican-American War marked such a pivotal moment in the history of both countries. The story is certainly better known in Mexico, which lost half its territory in the war and still remembers the niños heroes, a group of teenage cadets who bravely resisted the U.S. invasion of Mexico City and then leaped to their death off the barricades of Chapultepec Castle rather than surrender to the gringo invaders. But overall, on both sides of the border, the war is viewed mostly with regret — and, perhaps, as a cautionary tale on the unique perils of picking a fight with one’s neighbor.

For the United States, the war heralded the triumph of Manifest Destiny while also nurturing the 19th-century notion of the invincible Anglo-Saxon man, destined to rule over lesser peoples, brown and black. With the Treaty of Guadalupe-Hidalgo that ended the war, the United States increased its size by more than a third — virtually all of the American Southwest. But what most altered U.S. history was the consequent debate on whether the annexed territories should become free or slave states, a debate that helped trigger the American Civil War.

Several distinguished Americans condemned the war. Ralph Waldo Emerson, Henry David Thoreau and Walt Whitman censured it on ethical grounds. Abraham Lincoln argued that it had no legal justification. William Lloyd Garrison, abolitionist par excellence, summed the war up as follows:

If ever war was waged for basest ends,By means perfidious, profligate and low,It is the present war with Mexico,Which in deep guilt all other wars transcends.

Perhaps the most withering criticism of the war can be found in Ulysses S. Grant’s memoirs, where he writes that “(The) occupation, separation and annexation (of Texas) were, from the inception of the movement to its final consummation, a conspiracy to acquire territory out of which slave states might be formed for the American Union. … It was an instance of a republic following the bad examples of European monarchies, in not considering justice in their desire to acquire additional territory.” A page later, he affirms that “(The) Southern rebellion was largely the outgrowth of the Mexican war. Nations, like individuals, are punished for their transgressions. We got our punishment in the most sanguinary and expensive war of modern times.” In sum, Grant saw the Civil War as a divine retribution for what the U.S. did to Mexico.

If the United States chooses not to remember the war, Mexicans remember it too well — but with a mixture of pride and shame. In addition to the courageous niños héroes, they can take pride in the guerilla tactics of Father Jarauta, who repeatedly disrupted Winfred Scott’s supply lines. They might also remember the “Patricios,” the Irish-American soldiers who defected to Mexico rather than fight against fellow Catholics, as well as the countless Mexican campesinos forced to fight under incompetent generals like Antonio López de Santana. General Grant writes of these men:

The Mexican army of that day was hardly an organization. The private soldier was picked up from the lower class of the inhabitants when wanted; his consent was not asked; he was poorly clothed, worse fed, and seldom paid. He was turned adrift when no longer wanted. … With all this I have seen as brave stands made by some of these men as I have ever seen made by soldiers. … (The Mexicans) stood up as well as any troops ever did. The trouble seemed to be the lack of experience among the officers, which led them after a certain time to simply quit, without being particularly whipped, but because they had fought enough.

But the real embarrassment for Mexico is that their leaders failed to play to their advantages. The United States launched two invasions: one from Texas under General Zachary Scott and another from Veracruz on the eastern coast under General Winfred Scott. The Yankees were better equipped and better trained. But this alone cannot explain how they were able to cover hundreds of miles over difficult terrain before occupying Mexico City. What best explained their victory were the divisions within Mexican society, which in broad strokes consisted of three major groups: anticlerical liberals set on limiting the powers and capping the wealth of the church; conservatives who wanted to restore traditional rights to the church; and a third group, overlapping with the Catholic faction, who wanted to bring a monarch from Europe to govern Mexico. General Scott was particularly good at exploiting these divisions. For example, he bought supplies and gained free passage through Puebla merely by promising Puebla Catholics that he would respect the rights of the Church — about which he probably could not have cared less.

Mexican historian Heriberto Frías, in his book La Guerra Contra los Gringos, basically agrees with Grant’s diagnosis of the weaknesses of the Mexican army, writing that, “From that moment (of the first battle) there spread throughout the army … the most abominable dissension, one of the principal causes of the bloody catastrophes of that war of cursed memory.” He goes on to condemn the “repugnant and execrable egoism” of the Mexican generals, who could never agree on a coordinated plan.

Arguably, Mexico’s side of the story may best be found in a series of historical novels such as Guillermo Zambrano’s México por Asalto, Francisco Martín Moreno’s México Mutilado, Patricia Cox’s El Batallón de San Patricio, or Ignacio Solares’ La Invasión. Particularly interesting in Solares’ novel are his attempts to draw parallels between General Scott’s advance toward Mexico City and Hernán Cortés’ march toward Tenochtitlán. Both accomplished their goals by taking advantage of divisions within the local populace.

Since that fateful day in 1848 when Mexico signed away half of its territory, relations between the United States and Mexico have seen ups and downs. One recalls the sentence attributed to Mexican President (and autocrat) Porfirio Díaz: “Poor Mexico. So far from God and so close to the United States.”

In the last several decades, things seemed to be improving. The United States benefitted enormously from undocumented Mexican labor, and Mexican-descended U.S. citizens contribute much to the American mosaic. Similarly, NAFTA, for all its flaws, has benefitted both countries. But we should not forget that fatal war of the late 1840s and the fact that when things go badly, conflicts have a way of bringing out some of the worst in both countries.

ABOUT THE AUTHOR

Nicolas Shumway is the dean of humanities and a professor of Latin American literature at Rice University. Previously, he held positions at the University of Texas at Austin and Yale. His scholarship explores Latin American history and culture, with particular emphasis on Argentina, Brazil and Mexico. His best-known book, The Invention of Argentina, was selected by The New York Times as “a notable book of the year” and received Honorable Mention for the Bryce Wood Book Award of the Latin American Studies Association.